Flexible circuit sheet

ABSTRACT

A surgical instrument is disclosed having an elongated body portion having a proximal end and a distal end. The body portion is formed from a plastically deformable material such that the body portion can be bent between the proximal and distal ends from a first configuration to a second bent configuration and maintains the bent configuration. A flexible circuit having at least a pair of lead wires disposed around the body portion. The pair of lead wires are configured to conform to the bent configuration of the body portion such that they do not break during bending of the body portion. A tracking device adapted to cooperate with a navigation system to track the distal end of the instrument is coupled to the flexible circuit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/987,033 filed on Jan. 4, 2016, which is a continuation of U.S.application Ser. No. 13/751,032 filed on Jan. 25, 2013, which is acontinuation-in-part of U.S. application Ser. No. 13/748,150 filed onJan. 23, 2013, which is continuation-in-part of U.S. application Ser.No. 13/097,243 filed on Apr. 29, 2011, which claims the benefit of U.S.Provisional Patent Application No. 61/330,024 filed on Apr. 30, 2010.This application is a continuation of U.S. application Ser. No.14/987,033 filed on Jan. 4, 2016, which is a continuation of U.S.application Ser. No. 13/751,032 filed on Jan. 25, 2013, which is also acontinuation-in-part of U.S. application Ser. No. 12/400,951 filed onMar. 10, 2009. The disclosures of the above applications areincorporated herein by reference.

FIELD

The present disclosure relates generally to a flexible circuit sheetand, more particularly, a flexible circuit sheet for a surgicalinstrument.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Surgical procedures can be performed on anatomies such as the humananatomy for providing a therapy to the anatomy. One area of surgeryincludes procedures performed on facial cavities of a patient such as onthe ear, nose or throat (ENT). In such a procedure, a surgicalinstrument such as a suction device may be inserted into such a cavityto perform a procedure for example. Because the viewing angle of asurgeon at the area of interest can be obscured by the surroundingtissue of the cavity, the ability of a surgeon to effectively apply atherapy, such as a suction procedure, can be reduced. In someprocedures, it may also be difficult to effectively guide the surgicalinstrument through various shaped cavities of the anatomy. In an effortto address this difficulty, instruments have been developed that includeflexible elongated portions configured to be permanently flexible. Whilethese flexible instruments can conform to internal cavities of theanatomy, they do not retain any specific configuration, such that theyare generally not suitable for certain procedures, such as an ENTsuction procedure.

In navigation systems, instruments are provided with tracking devices.Sometimes, however, such tracking devices can be difficult to manipulateor cumbersome to couple to the instrument, especially instruments withthe flexible elongated portions. For example, it can be difficult toelectrically couple the tracking devices to associated lead wiresrelative to the flexible elongated portion. In other instances, thetracking devices can be positioned in a handle or proximal region of theinstrument such that if the distal tip moves or is moved relative to thehandle, the distal tip can no longer be accurately tracked.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

A surgical instrument, according to the present teaching has anelongated body portion having a proximal end and a distal end. The bodyportion has an inner diameter defining a first internal flow passagebetween the proximal and distal ends, and is formed from a malleablemetallic material such that the body portion can be bent between theproximal and distal ends from a first configuration to a second bentconfiguration and maintain the bent configuration. A handle portioncoupled to the proximal end of the body portion and including a secondinternal passage in fluid communication with the first internal flowpassage. A tracking device positioned adjacent the distal end andadapted to cooperate with a navigation system to track the location of adistal tip of the instrument, and including. A flexible circuit isdisposed around the body portion from the tracking device to the handleportion, the flexible circuit configured to conform to the bentconfiguration of the body portion such that they do not strain or breakduring bending of the body portion.

Further according to the present teachings, a surgical instrument isprovided having of an elongated body portion having a proximal end and adistal end. A tracking device is coupled to the elongated tubular bodyportion adjacent to the distal end. The tracking device is adapted tocooperate with a navigation system and includes a flexible circuitdisposed about the tubular body portion between the proximal and distalends.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present teachings.

DRAWINGS

The present teachings will become more fully understood from thedetailed description, the appended claims and the following drawings.The drawings are for illustrative purposes only of selected embodimentsand not all possible limitations, and are not intended to limit thescope of the present disclosure.

FIG. 1 is a perspective view of an exemplary navigation system accordingto the principles of the present disclosure;

FIG. 2 is a top plan view of an exemplary malleable suction instrumentfor use with the navigation system according to the principles of thepresent disclosure;

FIG. 3 is a side view of the exemplary suction instrument according tothe principles of the present disclosure;

FIG. 4 is a partial perspective view of a distal region of the exemplarysuction instrument having an exemplary flexible circuit sheet accordingto the principles of the present disclosure;

FIG. 5 is a partial side view of the distal region of the exemplarysuction instrument associated with the exemplary flexible circuit sheetaccording to the principles of the present disclosure;

FIG. 5A is an exploded view of an exemplary wire routing configurationaccording to the principles of the present disclosure;

FIG. 6 is a partial sectional view of the exemplary suction instrumentof FIG. 5 according to the principles of the present disclosure;

FIG. 7 is a partial view of a handle portion of the exemplary suctioninstrument according to the principles of the present disclosure;

FIGS. 8 and 9 illustrate views of exemplary alternative tracking sensorconfigurations according to the principles of the present disclosure;

FIG. 10 is a view of exemplary bent or formed configurations of theexemplary malleable suction instrument according to the principles ofthe present disclosure;

FIG. 11 is a partial perspective view of the distal region of theexemplary suction instrument illustrating an exemplary alternativetracking arrangement associated with the exemplary flexible circuitsheet according to the principles of the present disclosure;

FIG. 12 is a partial perspective view of the distal region of theexemplary suction instrument illustrating another exemplary alternativetracking arrangement according to the principles of the presentdisclosure;

FIG. 13A is an exploded perspective view of an exemplary configurationof the flexible printed circuit sheet according to the principles of thepresent disclosure;

FIG. 13B is a perspective view of the flexible printed circuit sheet ofFIG. 13A in an exemplary assembled configuration according to theprinciples of the present disclosure;

FIG. 14 is a perspective view of another exemplary flexible printedcircuit sheet according to the principles of the present disclosure;

FIG. 15 is a perspective view illustrating the flexible printed circuitsheet of FIG. 14 in a bent or flexed condition according to theprinciples of the present disclosure;

FIG. 16 is a perspective view of the flexible printed circuit sheet ofFIGS. 14 and 15 in a flexed condition conforming to an outer surface ofan exemplary instrument according to the principles of the presentdisclosure;

FIG. 17 is a partial side view of the distal region of the exemplarysuction instrument of FIG. 5 associated with the exemplary flexiblecircuit sheet and having wire management channels according to theprinciples of the present disclosure;

FIG. 18 is a perspective view of a patient tracking device having anexemplary flexible printed circuit sheet and associated coils accordingto the principles of the present disclosure;

FIG. 19 is a top view of another exemplary flexible printed sheetaccording to the principles of the present disclosure;

FIGS. 20A-20C are side views representing various exemplaryconfigurations of the flexible printed circuit sheet of FIG. 19according to the principles of the present disclosure;

FIG. 21 is a top plane view of an exemplary surgical instrument for usewith a navigation system according to the principles of the presentdisclosure;

FIG. 22 represents a top view of traces associated with the flexiblecircuit sheet of FIG. 23B;

FIG. 23A represents a malleable suction tube shown in FIG. 21 ;

FIG. 23B represents a conformed flexible circuit shown in FIG. 22A;

FIGS. 24A-240 represent perspective views of these exemplaryconfigurations of a flexible circuit sheet according to the presentdisclosure; and

FIGS. 25 and 26 represent cross-sectional views of the flexible circuitsheet shown in FIGS. 24A through 240 .

DESCRIPTION OF THE VARIOUS EMBODIMENTS

The following description is merely exemplary in nature and is notintended to limit the present disclosure, its application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and featureswith the various elements in each view being drawn to scale. Althoughthe following description is related generally to a flexible circuitsheet operatively associated with an exemplary flexible or malleablesuction instrument, it will be appreciated that the flexible circuitsheet can be associated with various devices and/or instruments,including various other surgical instruments.

Various exemplary embodiments are provided so that this disclosure willbe thorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, systems and/or methods, to provide athorough understanding of exemplary embodiments of the presentdisclosure. It will be apparent to those skilled in the art thatspecific details need not be employed, that exemplary embodiments may beembodied in many different forms and that neither should be construed tolimit the scope of the disclosure. In some exemplary embodiments,well-known processes, well-known device structures, and well-knowntechnologies are not described in detail.

FIG. 1 is a diagram schematically illustrating an overview of animage-guided navigation system 10 for use in the non-line-of-sitenavigating of a surgical instrument 100, such as a navigable malleablesuction device or suction instrument, according to various exemplaryembodiments of the present disclosure. Exemplary navigation systemsinclude those disclosed in U.S. Pat. No. 7,366,562, issued on Apr. 29,2008 to John H. Dukesherer et al. and U.S. Pat. App. Pub No.2008/0132909, published Jun. 5, 2008, to Bradley A. Jascob et al., bothincorporated herein by reference. Commercial navigation systems includethe StealthStation® AxiEM™ Surgical Navigation System sold by MedtronicNavigation, Inc. having a place of business in Louisville, Colo., USA.It should be appreciated that while the navigation system 10 and suctioninstrument 100 are generally described in connection with an ear, noseand throat (ENT) procedure, navigation system 10 and suction instrument100 can be used in various other appropriate procedures.

Generally, the navigation system 10 can be used to track a location ofan exemplary suction instrument 100, including a distal tip or endthereof, that includes an exemplary flexible printed circuit sheet 232associated therewith, as will be described herein. Navigation system 10can generally include an optional imaging system 20, such as afluoroscopic X-ray imaging device configured as a C-arm 24 and an imagedevice controller 28. The C-arm imaging system 20 can be any appropriateimaging system, such as a digital or CCD camera, which are wellunderstood in the art. Image data obtained can be stored in the C-armcontroller 28 and sent to a navigation computer and/or processorcontroller or work station 32 having a display device 36 to displayimage data 40 and a user interface 44. The work station 32 can alsoinclude or be connected to an image processor, navigation processor, anda memory to hold instruction and data. The work station 32 can includean optimization processor that assists in a navigated procedure. It willalso be understood that the image data is not necessarily first retainedin the controller 28, but may also be directly transmitted to theworkstation 32. Moreover, processing for the navigation system andoptimization can all be done with a single or multiple processors all ofwhich may or may not be included in the work station 32.

The work station 32 provides facilities for displaying the image data 40as an image on the display device 36, saving, digitally manipulating, orprinting a hard copy image of the received image data. The userinterface 44, which may be a keyboard, mouse, touch pen, touch screen orother suitable device, allows a physician or user 50 to provide inputsto control the imaging device 20, via the C-arm controller 28, or adjustthe display settings of the display device 36.

With continuing reference to FIG. 1 , the navigation system 10 canfurther include a tracking system, such as an electromagnetic (EM)tracking system 60. The discussion of the EM tracking system 60 can beunderstood to relate to any appropriate tracking system. The EM trackingsystem 60 can include a localizer, such as a coil array 64 and/or secondcoil array 68, a coil array controller 72, a navigation probe interface80, and the trackable suction instrument 100. Instrument 100 can includean instrument tracking device or devices 84, as will be discussedherein. Briefly, the tracking device 84 can include an electromagneticcoil to sense a field produced by the localizing coil arrays 64, 68 andprovide information to the navigation system 10 to determine a locationof the tracking device 84. The navigation system 10 can then determine aposition of a distal tip of the suction instrument 100 to allow fornavigation relative to the patient 34 and patient space.

The EM tracking system 60 can use the coil arrays 64, 68 to create anelectromagnetic field used for navigation. The coil arrays 64, 68 caninclude a plurality of coils that are each operable to generate distinctelectromagnetic fields into the navigation region of the patient 34,which is sometimes referred to as patient space. Representativeelectromagnetic systems are set forth in U.S. Pat. No. 5,913,820,entitled “Position Location System,” issued Jun. 22, 1999 and U.S. Pat.No. 5,592,939, entitled “Method and System for Navigating a CatheterProbe,” issued Jan. 14, 1997, each of which are hereby incorporated byreference.

The coil arrays 64, 68 can be controlled or driven by the coil arraycontroller 72. The coil array controller 72 can drive each coil in thecoil arrays 64, 68 in a time division multiplex or a frequency divisionmultiplex manner. In this regard, each coil may be driven separately ata distinct time or all of the coils may be driven simultaneously witheach being driven by a different frequency.

Upon driving the coils in the coil arrays 64, 68 with the coil arraycontroller 72, electromagnetic fields are generated within the patient34 in the area where the medical procedure is being performed, which isagain sometimes referred to as patient space. The electromagnetic fieldsgenerated in the patient space induce currents in the tracking device 84positioned on or in the suction instrument 100. These induced signalsfrom the tracking device 84 can be delivered to the navigation probeinterface 80 and subsequently forwarded to the processor 32. Thenavigation probe interface 80 can also include amplifiers, filters andbuffers to directly interface with the tracking device 84 in theinstrument 100. Alternatively, the tracking device 84, or any otherappropriate portion, may employ a wireless communications channel, suchas that disclosed in U.S. Pat. No. 6,474,341, entitled “SurgicalCommunication Power System,” issued Nov. 5, 2002, herein incorporated byreference, as opposed to being coupled directly to the navigation probeinterface 80.

The tracking system 60, if it is using an electromagnetic trackingassembly, essentially works by positioning the coil arrays 64, 68adjacent to the patient 32 to generate an electromagnetic field, whichcan be low energy, and generally referred to as a navigation field.Because every point in the navigation field or patient space isassociated with a unique field strength and directions, theelectromagnetic tracking system 60 can determine the position of theinstrument 100 by measuring the field strength and directions orcomponents thereof at the tracking device 84 location. The coil arraycontroller 72 can receive the induced signals from the tracking device84 and transmit information regarding a location, where locationinformation can include both x, y, and z position and roll, pitch, andyaw orientation information, of the tracking device 84 associated withthe tracked suction instrument 100. Accordingly, six degree of freedom(6 DOF) information can be determined with the navigation system 10.

Referring now to FIGS. 2-10 , the navigated malleable surgicalinstrument 100 will be described in greater detail. In one exemplaryconfiguration, the malleable surgical instrument 100 can be used forsuction, including fluid and tissue removal in ENT procedures. It shouldbe appreciated, however, that the navigated malleable surgicalinstrument 100 can be used in various other surgical procedures as maybe desired and can be provided in the form of a malleable or flexibleendoscope, a malleable or flexible catheter, and/or a malleable cannula.Thus, while the following description continues with reference to anavigated malleable suction instrument 100, the discussion is alsoapplicable to the surgical instruments discussed above.

Suction instrument 100 can include a tube assembly 110, a handleassembly 114 and a tracking sensor arrangement 118. Suction instrument100 can be configured for a single use such that it would be disposedafter such use. The tube assembly 110 can include a malleable elongatedtubular body 126 and an insert portion 130. The tubular body 126 caninclude an outer diameter 134 and an inner diameter 138 and can have afirst end 142 coupled to the handle assembly 114 and a second oppositeend 148 configured to receive insert portion 130, as shown in FIG. 6 .The second end 148 can include an internal annular recess 152 having aninner diameter 156 greater than the inner diameter 138 of the remainingportion of body 126, as also shown in FIG. 6 . The malleable elongatedbody 126 can be formed from various aluminum alloys, such as AL 3003-O,various stainless steel alloys, such as 304 annealed, as well as variousother materials including titanium, niobium, molybdenum, tantalum,nitinol, vinyl, and multi-lumen materials, such that it is malleable tofacilitate being bent or formed into various configurations andretaining the bent or formed configuration, as will be discussed herein.The body 126 can also be provided in various lengths and diameters,including 7, 9 and 12 French diameters.

The insert portion 130 can be configured to provide non-malleablesupport for at least the tracking sensor 84. Insert portion 130 caninclude an outer diameter 160 substantially equal to the inner diameter156 of annular recess 152, and an inner diameter 164 substantially equalto the inner diameter 138 of malleable elongated body 126, as also shownin FIG. 6 . In this manner, the substantially equal inner diameters 138,164 can provide for a substantially constant flow path 166 for suction.It should be appreciated, however, that the inner diameters 138, 164 canalso be provided with varying dimensions. The insert portion 130 canalso include an exemplary axial length of 10 to 15 mm, including 14 mm.Insert portion 130 can include a first end 172 and a second opposite end176. The first end 172 of the insert portion 130 can be received inannular recess 152, as shown in FIG. 6 . Insert portion can include arigid construction to facilitate receiving and housing tracking device84, as will be described herein. In this manner, insert portion 130 canbe formed or manufactured from stainless steel or other biocompatiblerigid materials such that insert portion 130 is not malleable likeelongated body 126. The insert portion can also include an exemplaryaxial length of approximately 10 mm.

Insert portion 130 can include a sleeve 190 received on an exteriorthereof, as shown in FIGS. 5 and 6 . Sleeve 190 can include an innerdiameter 194 substantially equal to the outer diameter of insert portion130, and an outer diameter 198 substantially equal to the outer diameter134 of body 126. It should be appreciated that sleeve 190 can also beconfigured with different diameters relative to body 126. Sleeve 190 canextend over a portion of insert 130 from the first end 172 of the insertportion 130 towards the second end, as shown in FIG. 6 . In oneexemplary configuration, sleeve 190 can extend from the first end 172and contact the first end 142 of body 126 when the insert portion 130 iscoupled to annular recess 152 of body 126. In another exemplaryconfiguration, sleeve 190 can extend from the first end 172 of bodyportion 130 in a similar manner as discussed above, but can stop shortof the first end 142 of body 126, as shown in FIG. 6 . Sleeve 190 can befixed to insert portion 130, and insert portion 130 can be fixed toannular recess 152 with an appropriate adhesive. Sleeve 190 can beformed of a polymeric material or other suitable materials. Sleeve 190can also include a first end 220 configured to substantially align withthe second end 176 of insert 130. The first end 220 can include arounded or chamfered blunt distal tip or end part 222 such that it canbe placed against surrounding tissue during a suction procedure withoutcutting or damaging such tissue. In one exemplary configuration, endpart 222 can extend over insert portion 130 so as to prevent cutting ordamaging tissue.

With particular reference to FIGS. 4 and 5 , sleeve 190 can include aplurality of flattened sections 206 configured to facilitate receivingand supporting the tracking sensor arrangement 118, as will be describedherein. In one exemplary configuration, sleeve 190 can include at leastthree flattened sections 206 configured to attachably receive trackingdevice 84. In this configuration, the tracking device 84 can includethree coil assemblies 214, as will be described herein. Briefly, in oneexemplary configuration, the three coil assemblies 214 can each includea cylindrical configuration as shown in FIGS. 4 and 5 , having anoverall axial length of approximately 1.5 mm to 2.7 mm, an overalldiameter of approximately 0.3 to 0.6 mm, and a plurality of wirewindings wound along a cylindrical base to form the cylindricalconfiguration. The plurality of windings can form the coil assembly 214having the generally uniform cylindrical configuration, as generallyshown in FIG. 5 . Each flattened section 206 can include a slot ordepression 218 formed therein and configured to receive a correspondingcoil assembly 214, as shown for example in FIGS. 5 and 6 . Each slot 218can be formed in the corresponding flattened section 206 at a 35 to 75degree angle, including a 55 degree angle, to a longitudinal axis 208 ofthe tube assembly 110. In one exemplary configuration, each slot 218 canbe formed at a 55 degree angle to longitudinal axis 208, as shown inFIG. 5 . Each of the three flattened sections 206 can be positionedequidistantly or 120 degrees around a circumference of sleeve 190 sothat the three coil assemblies 214 are therefore likewise positionedequidistantly around the circumference of sleeve 90, as also generallyshown in FIGS. 4-6 . It should be appreciated that the coil assembliescan also be coupled to the sleeve without the flattened sections 206,and can be aligned at different orientations relative to thelongitudinal axis, including parallel thereto. In this regard, thesleeve 190 can include an outer surface with a circular shape incross-section configured to receive the coil assemblies 214.

The coil assemblies 214 can include three coil assemblies as describedabove that cooperate with the navigation system 10 such that 6 DOFtracking information can be determined. It should be appreciated,however, that two coil assemblies 214 could also be used in conjunctionwith navigation system 10 such that 6 DOF tracking information can alsobe determined. In a configuration where three coil assemblies 214 areutilized, two of the three coil assemblies can be positioned at an anglerelative to the longitudinal axis 208 with the third coil assembly beingpositioned at an angle relative to the longitudinal axis 208 or parallelthereto. The three coil assemblies 214 can also each be positioned at anangle relative to each other. As discussed above, an exemplary angle ofthe three coil assemblies 214 relative to the longitudinal axis 208 canbe 55 degrees, which also provides for optimal packaging and spacing ofthe coil assemblies circumferentially around sleeve 190. It should beappreciated that while an angle of 55 degrees has been discussed, otherangles could be utilized with coil assemblies 214 and instrument 100 asmay be required. It should also be appreciated, as discussed above, thatthe coil assemblies could be positioned parallel or perpendicular to thelongitudinal axis 208.

In a configuration where tracking device 84 includes two coil assemblies214, the two coil assemblies can similarly be positioned equidistant or180 degrees spaced around an outer perimeter of sleeve 190, as well ascan each be positioned at an angle relative to each other and at anangle relative to the longitudinal axis 208 of the tube assembly 110. Inthis configuration, the two coil assemblies can also cooperate withnavigation system 10 such that 6 DOF tracking information can bedetermined. In one exemplary configuration, the two coil assemblies 214can be positioned at an angle of about 35 to 75 degrees, including about55 degrees relative to longitudinal axis 208 of the tube assembly 210.

With additional reference to FIGS. 8 and 9 , two exemplary coilassemblies 214A and 214B having alternative winding configurations areillustrated operatively associated with an exemplary tubular structure223 of an exemplary instrument. Coil assemblies 214A and 214B can eachinclude an overall non-linear shape as compared to the overallcylindrical configuration of coils assemblies 214 shown in FIG. 5 . Coilassembly 214A can include a central arcuate depression or concavity 224such that the depression 224 has a smaller outer diameter than opposedends 225 of the plurality of windings, as generally shown in FIG. 8 .The winding configuration of coil assembly 214A can provide an abilityto maximize an amount of coil windings on a base wire while workingtowards minimizing an overall outer dimension or size of an instrument.In this regard, coil assembly 214A is shown in FIG. 8 with the arcuatedepression 224 substantially conforming to an outer surface 226 of thetubular structure 223 such that the coil assembly or assemblies 214Aessentially nest around the outer surface 226 of the tubular structure.In this regard, because of the general clearance provided by acylindrical coil assembly positioned adjacent to an outer diameter ofthe tubular structure 223, a gap or space 221 on either end of the coilcan include additional windings without effectively increasing theoverall outer diameter of the entire assembly. This can allow forgreater or stronger sensitivity in the navigated space.

With particular reference to FIG. 9 , coil assembly 214B can include anoverall arcuate convex shape 227 configured to conform to and nestwithin an inner diameter 229 of the exemplary tubular structure. Similarto coil assembly 214A, such a configuration can provide for maximizingan amount of windings on the base wire while also working towardsminimizing the inner diameter 229 of the tubular structure 223 thatwould be required to receive one or more coil assemblies 214B.

With particular reference to FIGS. 5 and 5A, the tracking sensorarrangement 118 will now be described in detail. Tracking sensorarrangement 118 can include the tracking device 84 having the two orthree coil assemblies 214, as well as a first set of lead wires 228, theflexible printed circuit board or sheet 232 and a second set of leadwires 236. The first set of lead wires 228 can include a pair of leadwires 228A and 228B for each coil assembly 214, as generally shown inFIG. 5 . Each respective pair of lead wires 228A and 228B can be routedto a first end of a respective pair of circuit connections 240 onflexible printed circuit sheet 232. As will be discussed in greaterdetail below, the flexible circuit sheet 232 can facilitate improvingthe time and cost associating with terminating fine wires utilized inmedical and other instruments while also providing the flexibilitynecessitated for such instruments. It should be appreciated that whiletracking device 84 is described as having three coil assemblies, more orless coil assemblies can be utilized as may be desired or requireddepending on, for example, characteristics of the navigation systembeing utilized as well as the number of degrees of freedom desired.

The flexible printed circuit sheet 232 can include a flexible backing orbase layer 244 such that it can readily conform to the contour of anouter surface of the body 126, as shown for example in FIG. 4 . Theflexible printed circuit sheet 232 can wrap entirely or partially arounda perimeter of the body 126 and can be positioned adjacent the secondend 148 of body 126, as generally shown in FIGS. 5 and 6 . In thismanner, the insert portion 130, in its inserted position shown in FIG. 6, can be under all or substantially all of the flexible printed circuitsheet 232. The rigid insert portion 130 can thus prevent the malleablebody 126 from bending or flexing in a region of the flexible printedcircuit sheet 232. In one exemplary configuration, the flexible printedcircuit sheet 232 can be an integral part of sleeve 190. In anotherexemplary configuration, flexible printed circuit sheet 232 can bepositioned in a similar manner on sleeve 190. In this configuration,flexible printed circuit sheet 232 can be positioned on sleeve 190between coil assemblies 214 and the end of sleeve 190 adjacent thesecond end 148 of body 126.

The second set of lead wires can include three respective pairs of wires236A, 236B, 236C, as generally shown in FIG. 5 with reference to thepartial exploded view in FIG. 5A. It should be appreciated that whileFIGS. 2-5, 6-7 and 10 show the second set of lead wires 236 as oneelement, this is for illustration purposes only and it should beunderstood that the second set of lead wires shown in FIGS. 2-5, 6-7 and10 include the three respective pairs of lead wires 236A-C, as shown inFIG. 5A. Each pair of lead wires 236A-C can be twisted together andpositioned adjacent each other, as also shown in FIG. 5A. The twistedpairs 236A-C of wires can reduce electrical interference or cross-talkbetween each pair of adjacent lead wires as well as minimize pickup froman associated electromagnetic navigation system. Each pair of lead wirescan be connected to a single coil assembly 214 via the flexible printedcircuit sheet 232. The lead wires can also include a Teflon coating orother appropriate lubricous or friction reducing coating on an outersurface thereof. Each pair of lead wires 236A-C can be coupled to anopposite end of respective circuit pads 240 on the flexible printedcircuit sheet 232. It should be appreciated that the lead wires 228could alternatively extend up the body 126 as a twisted pair of leadwires without the use of the flexible printed circuit sheet 232, orcould extend up to and be terminated directly to the respective twistedpair of lead wires 236.

The second set of lead wires 236, which includes the three pairs oftwisted wires 236A-C, can be helically wound around elongated body 126from the flexible printed circuit sheet 232 to the second end 148, asgenerally shown for example in FIGS. 3-5A. The wires 236 can be woundaround the outside of body 126 at an angle α relative to thelongitudinal axis 208 of approximately 0 to 85 degrees, including about30 degrees, as generally shown in FIGS. 5 and 5A. Each revolution of thewires 236 around body 126 can be spaced apart from each other by adistance D of approximately 2 to 45 mm, including about 5 mm, as shownwith reference to FIG. 5 . In one exemplary configuration, the range caninclude from about 15-45 mm. The helical winding of the wires 236 at anacute angle relative to the longitudinal axis along with the relativelyclose spacing of the wires and the Teflon coating facilitate being ableto bend the malleable body 126 at significant angles, including beyondninety degrees, without breaking or otherwise damaging the wires 236, aswill be discussed herein. It should be appreciated that the wires 236can also be positioned along body 126 in a single revolution from theflexible printed circuit sheet 232 or the tracking device 84 to thesecond end 148. In this regard, the revolution spacing can be from about2 mm to a length of the body 126. The wires 236 can also be positionedalong body 126 from the flexible printed circuit sheet 232 to the secondend 148 without being wound around body 126.

Once the second set of wires 236 has been helically wound around theoutside of tubular body 126 to the first end 142, the wires can berouted into slots 254 in handle assembly 114 and connected to respectivelead wires of a cable connector assembly 258, as generally shown in FIG.7 . The cable connector assembly 258 can be connected to the navigationprobe interface 80, as generally shown in FIG. 1 . The handle assemble114 can include two half sections 264, with one half section being shownin FIG. 7 for illustration purposes.

With particular reference to FIG. 6 and continued reference to FIGS.2-5A, 7 and 10 , the tube assembly 110 can include a polymeric outerheat shrink 272 covering the entire assembly, as shown in thecross-sectional view of FIG. 6 . Thus, the heat shrink 272 can cover theelongated body 126, the insert portion 130, and the sensor arrangement118 including the wires helically wound along the body 126. The heatshrink 272 can provide an outer covering or shell over the tube assembly110 and sensor arrangement 118 while providing sufficient flexibilityfor both bending of the body 126 and slight relative movement of thehelically wound wires 236 as a result of the bending. In this regard,the wires can be moveably captured between the heat shrink and thetubular body. The heat shrink covering can also serve as an electricisolation barrier. It should be appreciated that while the heat shrinkcovering is only shown in FIG. 6 , it has not been shown in the othervarious views for clarification purposes only to better illustrate thesensor arrangement 118 and routing of wires 236. In this regard, itshould be understood that the heat shrink 272 can cover the tubeassembly 110 and sensor arrangement 118 shown in FIGS. 2-10 .

As discussed above, the handle assembly 114 can include multiplecomponents, such as for example two halves, with one of the halves shownin FIG. 7 receiving the first end of the suction tube assembly 110 influid communication with a suction passage 280 formed therein. Thesuction passage 280 can terminate at a connector 284 protruding from aproximal end of the handle (FIGS. 2 and 3 ) and can be configured toreceive a suction hose or other arrangement in fluid communication witha suction source (not shown). Once the wires are connected to the cableassembly and routed in the slots 254 as discussed above, the other halfof handle assembly 114 can connected and an adhesive can be used to bondthe handle halves together to form the handle as shown in FIGS. 2 and 3.

With particular reference to FIG. 2 , handle assembly 114 can include asuction adjustment feature 290 which can be in the form of a bore 292extending from an outer surface 294 of the handle assembly 114 and intofluid communication with the suction passage 280. In operation, asurgeon or user 50 of the instrument 100 can place their thumb oranother object over the bore 292 to vary an opening of the bore 292 andthus vary an amount of suction pressure realized in the flow path orpassage 166. For example, if the bore 292 is left completely open oruncovered, a majority if not all of the suction will be through the bore292 and not the first end 172 of insert portion 130. On the other hand,if the bore 192 is completely covered or closed off, a maximum amount ofsuction will be realized at end 172. Varying the opening of bore 292between fully closed and fully opened can therefore correspondingly varyan amount of realized suction at end 172.

In operation and with additional reference to FIG. 10 , the malleableelongated body 126 can be bent into various configurations, as generallyshown by the exemplary configurations 300A-D. The malleable nature ofbody 126 can provide the ability for body 126 to be bent into suchvarious configurations without kinking and can maintain the variousconfigurations until bent or shaped into another configuration. Further,malleable body 126 can be bent or shaped as discussed above withoutrequire additional tools, such as a mandrel to facilitate the bending.This is advantageous, for example, in that a surgeon can bend body 126multiple times by hand during a procedure in close proximity to thepatient without having to resort to additional tools or other equipmentto facilitate the bending while performing the procedure.

Moreover, the helically wound configuration of wires 236 along with theTeflon coating provides for the ability to bend malleable body 126 atvarious angles including through ninety degrees without breaking thewires. More specifically, by winding wires 236 helically around body 126at an angle relative to the longitudinal axis and at a close proximityto each other, the wound wires can conform to the bent shape and move orflex axially with the bent tube such that they do not strain and/orbreak during the bending. In addition, the Teflon coating provides addedlubricity for the wires to have relative motion between the tube and theouter shrink coating 272 during bending.

Further, by providing the tracking device 84 near the distal tip 222,the distal tip 222 of the suction instrument can be tracked to providesubstantially accurate position data for the distal tip of suctioninstrument 100 when out of a line of sight in a body cavity of patient34. This is particularly useful for the malleable suction instrument 100because, for example, the tip can be bent or moved relative to thehandle and still be tracked. On the other hand, if the tracking devicewas in the handle (such as in a hind tracked system) and the body 126was subsequently bent or shaped, the navigation system would no longerbe able to accurately track the position of the distal tip. In thisregard, the present teaching provide a tip tracked malleable suctioninstrument that can be bent or shaped into various configurations as maybe required during a procedure, and the distal tip can be accuratelytracked in any of the various bent positions.

In use, the patient 34 can be positioned on an operating table or otherappropriate structure and appropriate image data of a patient ornavigation space can be obtained, such as an ENT area. The image datacan be registered to the navigation space as is known in the art. Thesurgeon 50 can determine a shape of the malleable suction instrument 100to reach a target site and bend the suction instrument 100 to thedetermined shape where instrument 100 retains the bent shape, asdiscussed above. The bent or shaped surgical instrument 100 can then beguided to the target site with crosshairs representing the position ofthe distal tip of instrument 100 being superimposed on the image data.The crosshairs can show the tracked relative position of the distal tipas instrument 100 is navigated to the target site. In addition, ifduring navigation of the shaped instrument 100 to the target site, thesurgeon determines that the shaped configuration will need to bealtered, the surgeon can bend and/or reshape the instrument 100 to anewly shaped configuration and proceed again as discussed above.

With additional reference to FIG. 11 , an alternative tracking devicearrangement 84′ will now be discussed. As can be seen in FIG. 11 ,tracking device 84′ can include two or three wrapped coil assemblies214′ that can be used in place of the coil assemblies 214. Coilassemblies 214′ can be wrapped around sleeve 190 proximate the distaltip 222. In one exemplary configuration, the coil assemblies 214′ can beindividually wrapped around sleeve 190 in an overlapping manner with awrap axis having a non-normal and non-parallel angle to longitudinalaxis 208. In the exemplary configuration illustrated, coil assemblies214′ can be wrapped around sleeve 190 at an angle relative to each otherand longitudinal axis 208. In another exemplary configuration, coilassemblies 214′ can be wrapped around sleeve 190 and spaced axiallyapart from each other. A further discussion of the coil assemblies 214′can be found in U.S. application Ser. No. 12/770,181, filed on Apr. 29,2010 and entitled “Method and Apparatus for Surgical Navigation”, thedisclosure of which is incorporated by reference herein in its entirety.

With additional reference to FIG. 12 , another alternative trackingdevice arrangement 84″ is shown associated with instrument 100. Trackingdevice 84″ can also be used in place of tracking device 84 and caninclude a plurality of oval coil assemblies 214″ positioned about sleeve190 proximate distal tip 222. In one exemplary configuration, two tofour coil assemblies 214″ can be positioned about sleeve 190 proximatedistal tip 222. In the exemplary configuration illustrated, four coilassemblies 214″ can be circumferentially spaced around sleeve 190proximate distal tip 222, and an axial coil 304 can be positionedproximally of coil assemblies 214″, as shown in FIG. 12 . In oneexemplary configuration, two oval coil assemblies 214″ can be providedwith the axial coil 304. The two coil assemblies 214″ can also includetwo pair of coil assemblies 214″ provided with the axial coil 304.

The coil assemblies 214″ can be formed in various selected shapes, suchas elliptical, circular, or oval. In one exemplary configuration, theaxial coil 304 can be concentric with and wrapped around an outersurface of sleeve 190 or body 126, as shown in FIG. 12 . A furtherdiscussion of coil assemblies 214″ and axial coil 304 can be found inU.S. application Ser. No. 13/016,740, filed on Jan. 28, 2011 andentitled “Method and Apparatus for Image-Based Navigation”, thedisclosure of which is incorporated by reference herein in its entirety.

Turning now to FIGS. 13A-18 , the flexible printed circuit sheet 232,including various exemplary configurations thereof, will now bediscussed in greater detail. With particular reference to FIGS. 13A-13B,one exemplary configuration of the flexible printed circuit sheet 232 isshown in both an exploded view (FIG. 13A) and an assembled view (FIG.13B). Flexible printed circuit sheet 232 can include the flexiblebacking or base layer 244, one or more circuit or conductive traces,such as copper traces 350, positioned on a first or upper side 354 ofbase layer 244, coupling pads 358 associated with traces 350, and aninsulative layer 362 formed over at least the copper traces 350 andcoupled to base layer 244. It will be appreciated that while coppertraces 350 are shown positioned on upper side 354, the copper traces 350can also be positioned on an opposite lower side of base layer 244.While the discussion will continue with reference to the conductivetraces being copper traces 350, the conductive traces can also be formedfrom metal, nickel, gold, or copper with nickel/gold plating.

The flexible printed circuit sheet 232 can provide a mechanism forfacilitating fine gauge wire termination of associated sensors or coilsand lead wires, such as wires 228 and 236 of exemplary suctioninstrument 100. The flexible printed circuit sheet 232 can also enablemanufacturing and design flexibility in connection with use of circuitsheet 232 on instruments and other devices that are flexible and/orconformable. For example, conventional techniques for electricallyterminating sensor wires to lead wires can include directly connectingthe sensor wires to the lead wires via soldering. As can be appreciated,such a technique is very time and labor intensive considering that thesensor and lead wires can include 58 AWG wire with an outer diameter ofapproximately 0.01 mm. Indeed, such conventional techniques forsoldering the sensor wires to the lead wires often require performingthe process under a microscope or other magnifying apparatus, which canfurther drive cost and expense into the manufacturing process.

As will also be discussed in greater detail below, the exemplaryflexible circuit sheets discussed herein can provide for improvedefficiency and cost reduction in terminating such fine gauge sensor andlead wires, especially for medical instruments having size or volumeconstraints and that also require flexibility or conformability. In thisregard, the coupling 358 on the flexible circuit sheet 232 can be ordersof magnitude bigger than the outer diameter of the wires to beterminated, such as a 0.1 mm to 0.5 mm square pad, for example. In anexemplary configuration, the coupling pads 358 can have a large surfacearea for the wires to be terminated such that, for example, a primarylinear dimension of the coupling pads 358 can be orders of magnitudebigger than the outer diameter of the wires to be terminated. In oneexemplary configuration, the wires to be terminated can include an outerdiameter of between approximately 0.03 mm to 0.05 mm. In an exemplaryconfiguration, the wires to be terminated can include 58 AWG wire havingan outer diameter of approximately 0.01 mm. This can, among otherthings, facilitate easier and more efficient termination of the finegauge wire due to the larger size of coupling pads 358.

The base layer 244 can be formed form various materials havingappropriate insulative properties and appropriate material propertiessuch that base layer 244 is flexible and can conform to various surfacegeometries. For example, the base layer 244 (as well as the assembledprinted circuit sheet 232) can conform to the outer tubular surface ofthe malleable suction instrument 100. In one exemplary configuration,the flexible nature of flexible circuit sheet 232 can facilitatemovement with tube assembly 110 of malleable instrument 100 (e.g., FIG.10 ) once adhered thereto. In one exemplary configuration, the baselayer 244 can be formed from a polymeric material, including but notlimited to, a polyimide. In the exemplary configuration illustrated inFIGS. 13A-13B, the base layer 244 can include a length 366 ofapproximately 7 mm and a width 370 of approximately 3 mm. It should beappreciated, however, that the size and shape of base layer 244 can varydepending on a particular application.

The copper traces 350 can be positioned or printed in any desiredorientation on base layer 244, including substantially perpendicular toa longitudinal axis 374 of base layer 244. The copper traces 350 cansimilarly include varying lengths and widths depending on the particularconfiguration of flexible printed circuit sheet 232. In the exemplaryconfiguration illustrated in FIGS. 13A-13B, the copper traces 350 caninclude a length of approximately 1.25-3.0 mm and a width ofapproximately 0.15 mm. The copper traces 350 can include a thickness ofapproximately 0.01-0.04 mm.

The coupling pads 358 can be positioned or printed at ends of the coppertraces 350, as can be seen in FIGS. 13A-13B. The coupling pads 358 canbe formed in any desired shape, including the square or substantiallysquare shape 378 shown, for example, in FIGS. 13A-13B. The coupling pads358 can also be formed to have varying dimensions, including a dimensionor dimensions that is/are larger than a typical outer diameter of thewires that are to be coupled to the pads. As discussed above, such agreater dimension of the coupling pads 358 relative to the size of thewire can provide for easier soldering of the wires to the pads 358 andthus reduce time and manufacturing complexity associated with buildingan instrument requiring termination of fine gauge wires.

For example, the exemplary coupling pads 358 shown in FIGS. 13A-13B aresquare in shape and include a length and width of approximately 0.5 mm.Again, it should be appreciated that the length and width of couplingpads 358 can vary depending on the particular application of flexibleprinted circuit sheet 232. The coupling pads 358 can also be formed fromcopper and include a tinning material, such as tin/lead, nickel/goldand/or gold.

The insulative layer 362 can be positioned over the copper traces 350and coupled to the base layer 244 in any suitable manner that allows ordoes not inhibit the flexibility and conformability of the flexiblecircuit sheet 232. In one exemplary configuration, the insulative layer362 can be adhered to the base layer 244 and copper traces 350 with anadhesive. The insulative layer 362 can include a shape and/or width soas to cover or substantially cover the copper traces 350 between thecoupling pads 358 to insulate the traces 350 from external contact.Similar to the base layer 244, the insulative layer 362 can also beformed from a polymeric material, such as polyimide. In one exemplaryconfiguration, the insulative layer 362 can be a photoimageablecoverlay. As will be discussed in greater detail below, the insulativelayer 362 can include a thickness that is less than a thickness of thebase layer 244. In the exemplary configuration shown in FIGS. 13A-13B,the insulative layer 362 can include a rectangular shape correspondingto the exemplary symmetrical positioning of the copper traces 350 andcorresponding coupling pads 358.

To couple the flexible printed circuit sheet 232 to a structure, such asthe exemplary instrument 100, an adhesive 364 can be used. It should beappreciated, however, that other means for securing the flexible circuitsheet 232 to a structure can be used, so long as the means used does notinhibit the flexible nature of printed circuit sheet 232. In oneexemplary configuration, the adhesive 364 can be applied to a lower orsecond side 384 of base layer 244. In this regard, the second side ofbase layer 244 can be substantially smooth. It should also beappreciated that the adhesive 364 can also be applied to the structurein addition to or in lieu of being applied to base layer 244. In oneexemplary configuration, the adhesive 364 can include a medical gradepressure sensitive adhesive. In another exemplary configuration, theadhesive 364 can include a medical grade liquid or gel adhesive.

The exemplary flexible printed circuit sheet 232, in the exemplaryassembled configuration shown in FIG. 13B, can include a bound togetheror overall thickness 388 of between approximately 0.04-0.07 mm. In someexemplary embodiments, the overall thickness 388 can be onlyapproximately 0.04 mm. Stated another way, the assembled base layer 244,circuit traces and pads 350, 358 and insulative layer 263 can include anoverall thickness 388 of approximately 0.05 mm. It should beappreciated, however, that such a thickness can vary to be smaller orlarger depending on the particular application of the flexible printedcircuit sheet 232. Use of the pressure sensitive adhesive 364 canincrease the overall thickness 388 by approximately 0.025 mm to 0.05 mm.Similarly, use of the gel or liquid adhesive can increase the thickness388 by only 0.01 mm. Thus, the overall thickness 388 of the flexibleprinted circuit sheet 232, in various different configurations, can varyfrom 0.04 mm (without adhesive 364) to approximately 0.11 mm (withadhesive 364). As discussed above, such a minimal thickness 388 offlexible circuit sheet 232 provides for not only flexibility andconformability of the circuit sheet 232, but also applicability of theflexible circuit sheets to medical and other devices and/or instrumentsthat have very tight volume and/or packaging constraints.

For example, one of ordinary skill in the art will appreciate thatconventional printed circuit boards considered thin in the industry caninclude a thickness of 0.8 mm or greater and can be made from dielectriclayers laminated together with epoxy resin prepreg. Such materialscombined with such a thickness do not provide for the conventionalcircuit boards being flexible and thus they cannot conform to non-planarsurfaces and/or flex such that they cannot be used with a flexible ormalleable medical instrument. Further, such a thickness of 0.8 mm orgreater can preclude use of conventional printed circuit boards inmedical instruments or devices where maintaining a minimum thickness oroverall height is a critical parameter.

The very thin thickness 388 of the exemplary flexible circuit sheet 232,together with the polyimide material construction, can provide forsignificant flexibility and/or conformability of circuit sheet 232. Inthis regard, the exemplary flexible circuit sheet 232 having the overallthickness 388 and polyimide material construction can include a bendradius of approximately ten times the thickness 388. Thus, for theexemplary configuration of flexible circuit sheet 232 discussed herein,the bend radius can be approximately 0.4 mm to 0.7 mm depending on theoverall thickness 388 of the flexible printed circuit sheet 232. Such abend radius can provide for significant flexibility in conforming theflexible printed circuit sheet to or around tight radii associated withcompact or low profile medical instruments or devices.

With additional reference to FIGS. 14-16 , another exemplary flexibleprinted circuit sheet 232 will now be discussed and designated withreference numeral 232A. Flexible printed circuit sheet 232A can includesimilar properties and thickness dimensions as discussed above forflexible circuit sheet 232 such that like reference numerals refer tolike features or components. Flexible printed circuit sheet 232A isshown having an exemplary custom shape 392 configured for a particularmedical instrument or device. In the exemplary configuration illustratedin FIGS. 14-16 , flexible printed circuit sheet 232A can include one ormore apertures 396 configured to be positioned around and/or provideaccess to corresponding coil assemblies 214. The copper circuit traces350 can be printed in various patterns to accommodate the apertures 396and custom shape 392, as shown for example in FIG. 14 . It should beappreciated that while not shown for clarity purposes, the insulativelayer 362 can be custom shaped to include appropriate cutouts and anappropriate shape to cover the copper traces 350 while leaving thecoupling pads 358 of flexible circuit sheet 232A exposed.

As can be seen in FIGS. 15-16 , the flexible printed circuit sheet 232Acan be bent or flexed in various configurations to conform to variousinstrument or device shapes, such as the distal end of a malleableinstrument 100. In one exemplary configuration, the flexible printedcircuit sheet 232A can wrap around or substantially around the malleablesuction instrument 100. The flexible printed circuit sheet 232A can alsobend, flex or twist with the malleable suction instrument 100 during usethereof. In this regard, the flexible printed circuit sheet 232A canflex three-dimensionally. In the exemplary configuration shown in FIG.16 , flexible circuit sheet 232A can be adhered to the outer surface ofa component of malleable suction instrument 100 using, for example,adhesive 364. As discussed above, the lead wires 236A can beelectrically coupled, such as via soldering, to the appropriate couplingpads 358 and the coil assembly wires 228 can be soldered to thecorresponding pads 358, as also shown in FIG. 16 .

Turning now to FIG. 17 , flexible printed circuit sheet 232 is shownadhered to malleable suction instrument 100A, which is substantiallysimilar to malleable suction instrument 100 shown in FIG. 5 , except forchannels 402 formed in sleeve 190. Channels 402 can receive sensor orcoil wires 228 and provide a predetermined routing placement for wires228 relative to instrument 100A, as well as position wires 228 below anouter surface 406 of sleeve 190. Flexible printed circuit sheet 232 canconform to an outer surface of malleable suction instrument 100A and canprovide for efficient and cost effective termination of coil assemblywires 228 and lead wires 236, as shown for example in FIG. 17 . Forexample, flexible circuit sheet 232 can be flexed to correspond to aradius of the outer surface of the instrument so as to lay substantiallyflush or coplanar to the outer surface.

With particular reference to FIG. 18 , flexible printed circuit sheet232 is shown associated with an electromagnetic patient tracker device410. In the exemplary configuration illustrated, tracker device 410 caninclude the three coil assemblies 214 positioned equidistantcircumferentially around a longitudinal axis 414 of tracker device 410and can be configured to communicate with and be tracked by EM trackingsystem 60 of navigation system 10. The coils assemblies 214 can also bepositioned, in the exemplary configuration illustrated, at an angle,such as between forty-five degrees and fifty-five degrees relative toaxis 414 in a similar manner as coil assemblies 214 are positionedrelative to instrument 100 shown in FIG. 5 . It will be appreciated,however, that various other coil assembly 214 configurations and/ororientations can be utilized with patient tracker 410.

The flexible printed circuit sheet 232 can be positioned inside of orwithin a body 418 of tracker 410 as shown in FIG. 18 , or couldalternatively be positioned on an outer surface 422 of tracker 410. Inone exemplary configuration, flexible printed circuit sheet 232 can bebent or flexed to conform to the shape or contour of the surface it willbe adhered to, as shown in FIG. 18 . Sensor and lead wires (not shownfor clarity) can be soldered to the respective circuit pads in themanner discussed above.

Turning now to FIGS. 19 and 20A-20C, another exemplary configuration ofa flexible printed circuit sheet is shown at 232B. Flexible printedcircuit sheet 232B can be similar to flexible printed circuit sheet 232Asuch that like reference numerals refer to like components or featuresand only differences will be discussed in detail. Similar to flexibleprinted circuit sheet 232A, the flexible printed circuit sheet 232B caninclude base layer 244 having upper surface 354, conductive traces 350,solder or coupling pads 358 and top insulative layer 362.

The flexible printed circuit sheet 232B can include one or more pairedcircuit traces where the pairs of circuit traces are closely spacedtogether, as shown for example in FIG. 19 . By positioning the circuittraces in such a manner along the longitudinal axis 374, anyelectromagnetic interference and/or pickup from an associatedelectromagnetic navigation system can be minimized. In this exemplaryconfiguration, the conductive traces 350 can be parallel orsubstantially parallel to each other and spaced apart by less than 0.3mm, including 0.23 mm, in each pair of circuit traces. However, itshould be appreciated that other spacing may be utilized depending ondesign and other variables.

With particular reference to FIGS. 20A-20C, three exemplaryconfigurations (shown in side views) of the flexible printed circuitsheet 232B are shown. In these exemplary configurations, variousdifferent thicknesses of the flexible printed circuit sheet 232B areshown with and without adhesive, as will be discussed in greater detailbelow.

Referring to FIG. 20A, flexible printed circuit sheet 232B is shown in aconfiguration utilizing adhesive 364. In this configuration, the baselayer 244 can include a thickness of approximately 0.01 mm, theconductive traces and pads 350, 358 can include a thickness ofapproximately 0.04 mm and the insulative layer 362 can include athickness of approximately 0.02 mm. In the assembled configuration, theflexible printed circuit sheet 232B shown in FIG. 20A can include anoverall thickness 388 of approximately 0.07 mm without adhesive 364 andan overall thickness 388A of 0.11 mm with adhesive 364.

With reference to FIG. 20B, the flexible printed circuit sheet 232B isshown having a smaller overall thickness 388 of approximately 0.05 mmwithout adhesive 364 and an overall thickness 388A of 0.07 mm withadhesive 364. In this configuration, the base layer 244 can similarlyhave a thickness of approximately 0.01 mm, the conductive traces andpads 350, 358 can include a thickness of approximately 0.02-0.03 mm andthe insulative layer can include a thickness of approximately 0.01 mm.

Referring now to FIG. 20C, the flexible printed circuit sheet 232B isshown in another exemplary configuration having an overall thickness 388of approximately 0.04 mm. In this configuration, adhesive 364 may not beutilized. In such a configuration where adhesive 364 is not utilized, aheat shrink layer over the flexible printed circuit sheet 232B canoptionally be utilized to couple flexible printed circuit sheet 232B toan instrument, such as the suction instrument 100 discussed above. Inthis configuration of flexible printed circuit sheet 232B, the baselayer 244 can also include a thickness of approximately 0.01 mm, theconductive traces and pads 350, 358 can include a thickness ofapproximately 0.01-0.02 mm, and the insulative layer 364 can include athickness of approximately 0.01 mm.

Referring now to FIG. 21 , an alternate surgical instrument 100 will bedescribed in greater detail. Similar reference numerals will be used todescribe similar structures shown in FIGS. 2-4 . In one exemplaryconfiguration, the surgical instrument 100 can be a malleable tool usedfor suction, including fluid and tissue removal in ENT procedures.Associated with the surgical instrument 100 is a flexible circuit 430 totransport electrical signals between the navigation probe interface 80and a plurality of navigation coils 214. The flexible circuit 430provides termination pads (not shown) for fine coil wires as well ascable wires and conductive traces 350 to bring electric connectivity toportions of the surgical instrument 100. As described further below, theconductive traces 350 are configured to minimize the pickup of strayelectromagnetic noise.

The flexible circuit 430 described in detail below can be usable inother tracked medical devices or any other devices where tracking ornavigating a distal tip of a device is desired. Thus, while thefollowing description continues with reference to a navigated surgicalinstrument 100, the discussion is also applicable to the surgicalinstruments discussed above and any other appropriate instruments thatrequire tracking or navigation of instruments that require substantiallysmooth exterior surfaces so as to not adversely interact with patienttissue. This is in contrast to existing instruments that have discretewires wrapped around the outside of the instrument causing a ribbedeffect. For example, the flexible circuit can be used in a micro coilbased core tracker assembly, slanted coil based cranial stylets, biopsyneedles, or other navigated instruments requiring challenging volumetricpackaging constraints.

Surgical instrument 100 can include a tube assembly 110, a handleassembly 114, and a tracking sensor arrangement 118. Surgical instrument100 or portions thereof can be configured for a single use such that itwould be disposed of after such use. The tube assembly 110 can include amalleable elongated tubular body 126 and an insert portion 130. Themalleable tubular body 126 can be formed from a malleable metallicmaterial such that the tubular body 126 body portion can be bent betweenthe proximal and distal ends from a first configuration to a second bentconfiguration and maintain the bent configuration.

The tubular body 126 can include an outer diameter 134 and an innerdiameter 138 and can have a first or proximal end 142 coupled to thehandle assembly 114 and a second opposite or distal end 148 configuredto receive insert portion 130. As best seen in FIG. 4 , the second end148 can include an internal annular recess 152 having an inner diameter156 greater than the inner diameter 138 of the remaining portion of body126. The body 126 can also be provided in various lengths and diametersincluding, by way of example, lengths from 50 mm-500 mm and including 7,9 and 12 French diameters. The insert portion 130 can be configured toprovide non-malleable support for at least the tracking sensor 84.

Insert portion 130 can include a sleeve 190 received on an exteriorthereof. Sleeve 190 can include an inner diameter 194 substantiallyequal to the outer diameter of insert portion 130, and an outer diameter198 substantially equal to the outer diameter 134 of body 126. Theinsertion of the sleeve 190 into the first end 148 of the body canfacilitate the electronic coupling of tracking coils with the navigationsystem. Alternatively, electronic coupling can be accomplished usingsoldering techniques. It should be appreciated that sleeve 190 can alsobe configured with different diameters relative to body 126.

FIG. 22 represents a top view of conductive traces 436, 438 associatedwith the flexible circuit 430 of FIG. 21 . The conductive traces 436,438 are twisted to form loops configured to have opposite handednessfrom its nearest neighbors. The alternative handedness effectivelycancels electromagnetic noise. In this regard, the twisted pairsminimize electromagnetic pickup that would degrade navigationperformance. The twisted pair configuration is formed usingthrough-substrate or base layer 434 connections, as is illustratedexemplarily in FIG. 24D on the flexible base layer 434, and provides theneeded form factor. In this regard, the flexible circuit 430 protrudesfrom the nominal surface radius of the body portion 126 by less thanabout 0.05 mm, thus minimizing interaction of the device with patienttissue. In other words, the thickness of the flex circuit is 0.08 mmwhich is less than the thickness of the twisted wires 0.4 to 0.5 mm. Theconductive traces 436, 438 have first and second coupling pads 350 and358 disposed at a first proximal end 142 and a second set of couplingpads 350 and 358 disposed at the second distal end 148, wherein thelength of the flexible circuit 430 extending from the first proximal end142 to the second distal end 148 is of the elongated body 126.Furthermore, the profile of the construction utilizing the flexiblecircuit 430 is substantially smoother and more uniform than the ribbedprofile of the twisted wire configuration.

With particular reference to FIGS. 23A and 23B, the flexible circuit 430having one or more, including three pairs of conductive traces 436, 438as illustrated in FIG. 22 is shown. The flexible circuit 430 isgenerally disposed around the body portion 126 and extends from thetracking device 84 from the second distal end 148 to the first proximalend 142 and handle assembly 114. The flexible circuit is configured toconform to the bent configuration of the body portion 126 such that itdoes not strain or break during bending of the body portion 126. Theflexible circuit 430 can be longitudinally or helically disposed arounda portion of the body portion 126 from the tracking device 84 to thehandle assembly 114. If longitudinally disposed, the flexible circuit iscurved transverse to the longitudinal axis of the flexible circuit 430to conform to the curvature of the instrument shaft, as shown in FIG.23A. The flexible circuit 430 can have a sinusoidal periphery or have aperiphery formed of a plurality of curved line segments. If helicallydisposed, the flexible circuit 430 is wrapped helically around thelongitudinal axis as is shown in FIG. 21 . To allow the body portion 126to curve when the flexible circuit 430 is wound around the body portion126, the flexible circuit can define gaps 433 which allow andaccommodate for compression and tension of an external surface of thebody portion 126. When the outer portion of the body portion 126 is intension, the gaps 433 can expand, while the inner portion during thebending of the body portion 126.

FIG. 23A represents the malleable tube 110 shown in FIG. 21 . As shown,the flexible circuit 430 extends from the first proximal end 142 of thebody portion 126 to the second distal end 148 of the body portion 126. Aserpentine shaped flexible circuit 430 is laid longitudinally wrappedaround the body portion 126. As described below, the conductors in theflexible circuit 430 can be generally parallel (see FIG. 24F) or formtwisted pairs (See FIG. 24A) to allow the navigation system to properlyaccount for electromagnetic noise. Each twist in the twisted pairproduces a small loop to reduce electromagnetic coupling noise.

FIG. 23B represents the flexible circuit 430 in a planar manner beforeit has been conformed as is shown in FIG. 23A. The serpentine shapedflexed circuit 430, when wrapped around the body portion 126, definesthe gaps 433 along edges of the flexible circuit. It is envisioned themaximum radius of curvature of the body portion 126 may be regulated bythe size and positions of the defined gaps 433.

FIGS. 24A-240 represent perspective views of exemplary configurations ofthe flexible circuit 430 according to the present teachings. Generally,the flexible circuit 430 has the first and second conductive traces 436,438 which are parallel or are twisted to reduce the influence ofelectromagnetic noise on the tracking system. The flexible circuit 430can have a base layer 434 formed of a thin insulative material such aspolyimide, polyethylene, terephthalate, latex, nitrile rubber,polysiloxanes, silicone, polyurethane, polyether block amide (trade namePEBAX), a first circuit trace 436 having a first upper portion 460 ofthe trace formed on a first upper side 441 of the base layer 434, and asecond circuit trace 438 having a second lower portion 462 formed on ansecond lower side 442 of the base layer 434. The flexible circuit 430can take any number of shapes which allow the flexible circuit 430 andmedical device to bend.

The base layer 434 and insulative layers include material properties anda thickness configured to facilitate the flexible circuit 430 beingflexible such that the flexible circuit 430 is adapted to conform to anexterior surface of the elongated body 126, as well as allow theelongated body 126 to bend along the longitudinal axis of the bodyportion 126. The flexible circuit 430 can have various componentsdisposed between the proximal and distal ends 143, 149. In this regard,various electrical components such as amplifier or tracking coils can beattached. For example, coil assemblies 214 can be coupled to theflexible circuit 430 at predetermined locations between the proximal anddistal end 143, 149. In other words, a single coil assembly can belocated at the second distal end 149, multiple coils can be locatedalong the length of the flexible circuit 430.

As shown in FIG. 24A, the conductive traces 436, 438 can form a twistedpair configuration. The first trace 436 runs along the first upper side441 and crosses over a second trace 438 positioned on an opposite secondside 442 at an acute angle A. The first trace 436 then passes throughthe insulator or base layer 434 and runs along the second lower side442. A second trace runs along the second lower side 442 and crossesover a first trace 436 positioned on the first upper side 441 at theacute angle A. The first and second conductive traces 436, 438 crossfrom over to under at electrical vias 439. The vias 439 extendtransversely through the base layer 434 to connect the conductive tracefrom the first upper side 441 to the second lower side 442.

FIGS. 24B and 24C represent a flexible circuit 430 having three twistedpair configurations as shown in FIG. 24A as they would be wrapped aroundan elongated body 126. As shown, coupling pads 358 are provided forcoupling to the leads of three coils at the second distal end 149 or tothe coupling cable wires at the first proximal end 143. The vias 439 aredisposed between the overlapping conductive traces 436, 438 were thetraces are located on opposite sides of the base layer 434. Generally,the conductive traces 436, 438 are positioned adjacent and parallel toeach other to minimize conductor loop size.

As shown in FIG. 24D, the loop area 446 can be reduced by placing thefirst trace 436 directly over the second trace 438 on the base layer 434for a majority of the length of the trace except where the conductivetraces separate to form vias 439 in passing areas 448. In other words,for short distances, the conductive traces separate enough to allow thetraces to pass through the base layer 434 to the other side. At thispoint, the traces return to a position where they are parallel to eachother. The loop area can further be reduced by reducing the thickness ofthe insulative base layer 434. It is envisioned the base layer 434 canhave a thickness of about 0.025 mm. The base layer 434 can be formed ofpolyimide, polyethylene, terephthalate, as well as a thin elasticinsulative base layer 434. The base layers 434 can be latex, nitrilerubber, polysiloxanes, silicone, polyurethane, polyether block amide orPEBAX.

As shown in FIG. 24E, by using multiple base or insulative layers, andplacing oppositely handed twisted pairs intertwisted with an adjacentpair of conductors, further noise cancellation can be accomplished. Theoppositely handed twisted pairs connect in parallel, adding redundancyto this canceled double twisted pair configuration. As previouslydiscussed, conductive traces 436, 438 are periodically passed throughfrom a first upper side 441 of the base layer 434 to a second lower side442 of the base layer 434 to form the twisted configuration. As can besee, up to four conductive traces 436, 438 can be separated byinsulative layers and run in parallel with the second pair being atwisted pair with opposite handedness to the first pair of conductivetraces. These conductive traces are shuttled through various basedlayers 434 to form the twisted pair constructions.

As shown in FIGS. 24F and 24G, the pair conductive traces 436, 438 neednot be in a twisted pair configuration. FIG. 24F depicts a noiseminimizing parallel pair set. The configuration uses the thinness of thebase layer to minimize noise. FIG. 24G depicts a double oppositelyoriented parallel pair with the second pair being a twisted pair withopposite handedness to the first pair of conductive traces. The proximalend 143 of the flexible circuit 430 has a pair of coupling pads 358. Thecoupling pads 358 are coupled to a pair of parallel conductive traces436, 438 which are directly over one another, each disposed on opposingsides 441, 442 of the base layer 434. At the distal end 149 of the baselayer 434, another pair of coupling pads 358 are provided to couple theflexible circuit to the tracking coils or tracking device 84. Insituations where there are numerous conductive traces on the same baselayer 434, coupling pads can be found on first and second (top orbottom) sides of the base layer 434. This allows for the convenientcoupling of tracking devices to the base layer 434 using soldering orconnectors.

As shown in FIGS. 24H-24N, the flexible circuits can have a sinusoidalform. Each conductive trace 436, 438 can be defined on a single side ofthe base layer 434 and can have radius of curvature R which is betweenthe outer and inner radiuses of curvature of the base layer 434.Alternatively, as shown in FIGS. 24I and 24J, the pairs of conductivetraces can be formed in twisted pairs by alternating position onopposite sides of the flexible circuit as described above. The paircrossovers or vias 349 occur at locations along the curve. Generally,the vias 349 are positioned transverse to the longitudinal axis of thebody portion 126 or base layer 434. As shown in FIG. 24J, the vias occurat sinusoidal midpoints wherein at FIG. 24I the vias occur at sinusoidalminimums or maximums. The vias 349 are between peaks and valleys in thesinusoidal substrate in order to minimize the mechanical stresses on theelectrical vias 349. Generally, the through paths or vias 349 will beformed perpendicular to the longitudinal axis of the tool.

As shown in FIGS. 24K and 24L, three pair of conductive traces can beformed on a single serpentine or sinusoidal shaped base layer 434. Inother words, the conductor traces 436, 438 can be three pairs ofconductive traces in a single serpentine flexible circuit 430. As can beseen, the position of the vias 439 can be staggered along the length ofthe flexible circuit so each new curvature represents a new location forthe via 439. Alternatively, the vias 439 can be staggered adjacent tothe centerline of the flexible circuit.

As shown in FIGS. 24M-24N, a pair of serpentine flexible circuits 430can be braided together to form a flat twisted pair by combining twoindividual sinusoidal patterned base layers 434, each with threesinusoidally patterned traces explicitly braided into three flat pairs.The base layers 434 can be joined at the proximal end 142 to facilitatethe coupling of the tracking device 84. The use of several flexiblecircuits 430 in this configuration can provide a proper level ofrigidity of the body portion 126.

FIG. 240 represents an alternate flexible circuit 430 having a braidedpair configuration. The leads 436, 438 are disposed through the baselayer and wrapped around apertures 440 defined in the base layer 344. Asshown, the base layers 434 form the braided pair configuration and canalternate sides of the flexible circuit 430 as described above.

Referring to FIG. 25 , a cross-sectional view of the flexible circuit430 is shown in a configuration utilizing a pressure sensitive adhesive364. In this configuration, the base layer 434 can include a thicknessof approximately 0.01 mm, the conductive traces 436, 438 and pads 350,358 can include a thickness of approximately 0.04 mm, and the insulativelayer 362 can include a thickness of approximately 0.02 mm. In theassembled configuration, the flexible printed circuit sheet can includean overall thickness 388 of approximately 0.07 mm without adhesive 364and an overall thickness 388 of 0.11 mm with adhesive 364.

With reference to FIG. 26 , the flexible circuit 430 is shown having asmaller overall thickness 388 of approximately 0.05 mm without adhesive364, and an overall thickness 388 of 0.07 mm with adhesive 364. In thisconfiguration, the base layer 244 can similarly have a thickness ofapproximately 0.01 mm, the conductive traces 436, 438 and pads 350, 358can include a thickness of approximately 0.02-0.03 mm, and theinsulative layer can include a thickness of approximately 0.01 mm.

It will be appreciated that while various configurations of flexibleprinted circuit sheets have been discussed herein, other configurationscan be utilized taking advantage of the thin, compact and conformablefeatures of such flexible printed circuit sheets. In this exemplaryconfiguration, such a flexible printed circuit sheet could include alength configured to be helically wound from the distal end 148 to thehandle assembly 114.

While one or more specific examples have been described and illustrated,it will be understood by those skilled in the art that various changesmay be made and equivalence may be substituted for elements thereofwithout departing from the scope of the present teachings as defined inthe claims. Furthermore, the mixing and matching of features, elementsand/or functions between various examples may be expressly contemplatedherein so that one skilled in the art would appreciate from the presentteachings that features, elements and/or functions of one example may beincorporated into another example as appropriate, unless describedotherwise above. Moreover, many modifications may be made to adapt aparticular situation or material to the present teachings withoutdeparting from the essential scope thereof.

What is claimed is:
 1. A surgical instrument, comprising: an elongatedbody extending from a proximal end to a distal end, the elongated bodyis tubular-shaped and has a first internal passage extending between theproximal end and the distal end; a handle coupled to the proximal end ofthe elongated body, the handle having a second internal passage in fluidcommunication with the first internal passage; and a first tracking coilpositioned adjacent to the distal end of the elongated body, the firsttracking coil extending between a first end and a second end and havingan overall non-linear shape to conform to a surface of the elongatedbody, wherein a diameter of the first tracking coil between the firstand second ends is different from a diameter at the first and secondends to maximize an amount of coil windings while minimizing a dimensionof the elongated body.
 2. The surgical instrument of claim 1, whereinthe dimension is an outer diameter of the elongated body or an innerdiameter of the elongated body.
 3. The surgical instrument of claim 1,wherein: the first tracking coil is disposed on an exterior surface ofthe elongated body; the first tracking coil has a first side and asecond side, which extend between the first and second ends of the firsttracking coil; the first side opposes the second side; the first sidehas a concave shape that matches a convex shape of the exterior surfaceof the elongated body; the second side has a planar shape; and the firsttracking coil includes more windings at the first and second ends of thefirst tracking coil than at a center of the first tracking coil.
 4. Thesurgical instrument of claim 1, wherein: the first tracking coil isdisposed on an interior surface of the elongated body; the firsttracking coil has a first side and a second side, which extend betweenthe first and second ends of the first coil; the first side opposes thesecond side; the first side has a convex shape that matches a concaveshape of the interior surface of the elongated body; the second side hasa planar shape; and the first tracking coil has more windings at acenter of the first tracking coil than at the first and second ends ofthe first tracking coil.
 5. The surgical instrument of claim 1, whereinthe elongated body includes a tubular insert at the distal end and asleeve configured to be received over the insert, wherein the firsttracking coil is coupled to the sleeve adjacent to the distal endthereof.
 6. The surgical instrument of claim 1, further comprising apair of lead wires helically wound around the elongated body from thefirst tracking coil to the handle.
 7. The surgical instrument of claim6, further comprising a printed circuit board positioned adjacent thefirst tracking coil, wherein the printed circuit board is configured tocouple the pair of lead wires to the first tracking coil.
 8. Thesurgical instrument of claim 1, further comprising a second trackingcoil positioned adjacent the distal end of the elongated body, thesecond tracking coil extending between a first end and a second end andhaving an overall non-linear shape to conform to a surface of theelongated body, wherein a diameter of the second tracking coil betweenthe first and second ends is different from a diameter at the first andsecond ends of the second tracking coil to maximize an amount of coilwindings while minimizing the dimension of the elongated body.
 9. Thesurgical instrument of claim 1, wherein the first tracking coil iswrapped around a core and mounted adjacent to the distal end of theelongated body.
 10. A surgical instrument, comprising: a body having aproximal end and a distal end, wherein the body is tubular-shaped andhas an internal passage extending between the proximal end and thedistal end; an insert received in the distal end of the body; a sleevereceived over the insert at the distal end of the body; and a trackingcoil positioned on an exterior surface of the sleeve, the tracking coilextending between a first end and a second end and having a first sideand a second side, the first side opposes the second side and the firstside has a concave shape that matches a convex shape of the exteriorsurface of the sleeve, the second side has a planar shape, wherein thetracking coil has more windings at the first and second ends of thetracking coil than at the center of the tracking coil.
 11. The surgicalinstrument of claim 10, wherein the body is formed from a malleablematerial such that the body can be bent between the proximal and distalends from a first configuration to a second bent configuration.
 12. Thesurgical instrument of claim 11, wherein the insert prevents bending orflexing in a region where the insert is received in the distal end ofthe body and wherein the insert provides rigid support for the sleeve toprevent bending of the sleeve.
 13. The surgical instrument of claim 10,wherein the distal end of the body includes an annular recess definingan internal shoulder and the insert is partially received within thedistal end in the annular recess engaging the internal shoulder.
 14. Thesurgical instrument of claim 13, wherein the sleeve is adjacent to andnot in contact with the distal end of the body when positioned on theinsert.
 15. The surgical instrument of claim 12, further comprising aprinted circuit board positioned at the distal end where the insert isreceived in the body to prevent bending or flexing of the printedcircuit board.
 16. A surgical instrument, comprising: a body having aproximal end and a distal end, wherein the body is tubular-shaped andhas a first internal passage extending between the proximal end and thedistal end; an insert received in the distal end of the body; a sleevereceived over the insert at the distal end of the body; and a trackingcoil positioned on an interior surface of the sleeve, the tracking coilextending between a first end and a second end and having a first sideand a second side, the first side opposing the second side and the firstside has a convex shape that matches a concave shape of the interiorsurface of the sleeve, the second side has a planar shape, wherein thetracking coil has more windings at a center of the tracking coil than atthe first and second ends of the tracking coil.
 17. The surgicalinstrument of claim 16, wherein the insert prevents bending or flexingin a region where the insert is received in the distal end of the bodyand wherein the insert provides rigid support for the sleeve to preventbending of the sleeve, wherein the distal end of the body includes anannular recess defining an internal shoulder and the insert is partiallyreceived within the distal end in the annular recess engaging theinternal shoulder.
 18. The surgical instrument of claim 16, furthercomprising a handle coupled to the proximal end of the body, wherein thehandle includes a second internal passage extending through the handleand in fluid communication with the first internal passage.
 19. Thesurgical instrument of claim 18, further comprising a pair of lead wireswound around the body from the tracking coil to the handle.
 20. Thesurgical instrument of claim 16, wherein the tracking coil is wrappedaround a core.